Process of improving and preforming binding



July 24, 1962 .1. D. HOPKINS 3,045,463

PROCESS OF IMPROVING AND PREFORMING BINDING Filed April 27, 1961 II M INV EN TOR.

United States Patent Ofiice Patented July 24, 1.962

This invention comprises a novel process of improving and preforming leather binding strip material. This material comes to the supplier in a great variety of textures varying in the piece and from piece to piece in hardness, brittleness and stifiness. It is customarily applied to parts of shoe uppers simultaneously with a stiching operation and under these conditions such variations in the character of the strip cause uneven application of the binding, slowing down of the sewing machine, variation in the length of the stich and even breakage of the binding strip.

The present invention is based on my discovery of a process by which the usual commercial run of leather binding material may be rendered substantially uniform as to texture and preformed to an extent that permits it to travel smoothly at a uniform rate when applied to parts of an upper by single stitching in U-Shaped formation or by flat stitching and turning. By the process of my invention therefore it is possible to utilize large quantities of binding of heterogeneous character with all the facility now found only in binding of the highest and most expensive grades. The application of the invention may be still further extended to prepare leather binding backed with textile reinforcing tape.

The novel process is characterized by the steps of folding the strip to present overlapping marginal portions and subjecting the overlapped portions to progressive rolling pressure, meantime confining the fold vertex of the strip Within a passage of greater dimension than'the combined thickness of the overlapped portions. Preferably this passage is substantially circular in cross-section and of suificient diameter to permit the fold vertex of the binding to assume a more or less circular contour while under treatment. The stripping is treated progressively throughout its entire width, that is to say, its overlapping portions are subjected to pressure while the adjacent portions of. the fold vertex are confined as above stated.

Upon completion of the process the binding reassumes a substantially fiat condition, although on close examination a slight transverse concavity may be detected. Apparently the fibers of the binding strip have been broken so that it may readily be conformed to the shape it is to assume when applied to the shoe part. The result however of the treatment is most surprising and unpredictable in facilitating the smooth, rapid and uniform passage of the stripping through the sewing machine guides in the stitching operation.

These and other features of the invention will be best understood and appreciated from the following description of a preferred manner of carrying out my novel process as illustrated in the accompanying drawings in which:

FIG. 1 is a diagrammatic view showing the operation of applying and stitching a binding strip in U-shaped formation,

FIGS. 2 and 3 are views of the treated binding strip in cross section on an enlarged scale,

FIG. 4 is a viewin cross section showing a binding strip applied in turned formation,

FIG. 5 is a fragmentary view in elevation of the apparatus for carrying out the process,

FIGS. 6, 7 and 8 are views in cross section on the lines respectively 6-6, 7-7 and 8-8 of FIG, 5 and on an enlarged scale, and

FIG. 9 is a view in cross section indicating the treatment of a binding strip for application in an unequal fold In FIG. 1 a shoe upper part 10 is represented as in place in the sewing machine having a needle bar 11 and a guide 12 through which the binding strip 13 is drawn and shaped in approaching the sewing point. The function of the guide 12 is progressively to impart a U-shaped formation to the binding strip and guide it to the shoe part so that it encloses the edge thereof. As the binding strip is thus applied it is secured in position by the stitch line 14. As already explained it is extremely important that the binding strip should run smoothly and uniformly through the guide 12 and that very desirable result is brought about by the process of treatment now to be described.

The binding strip 13 comes to the customer in the form of a leather strip which may be several hundred feet long, from one-half to three-quarters of an inch in width and .03 to .06 inch in thickness. It is first folded longitudinally to present overlapping marginal portions as shown in FIGS. 8 and 9, ad then these overlapped portions are progressively subjected to a heavy rolling pressure as by rolls 20-23, while the fold vertex portion of the strip is confined within a passage formed in the rolls which are larger in dimension than the combined thickness of the overlapping portions and preferably of substantially circular contour. As shown in FIG. 8 the roll 20 has a circumference in which is formed a semi-circular circumferential groove 21 and a rectangular circumferential recess 22. The roll 23 is correspondingly formed, being provided with a semi-circular circumferential groove 24 and a rectangular projecting flange 25 which is received in the recess 22 of the roll 20.

The'binding strip 13 is directed to these rolls by a guide 26 which comprises a pair of branches converging toward the bight of the rolls 20 and 23 and contain a 'U-shaped passage which imparts to the binding strip the desired overlapping relation of its marginal portions as is shown in FIG. 8. In practice the rolls 2.0 and 23 are driven slowly and under heavy pressure in the direction of the arrows in FIG. 5, drawing the binding strip through the guide 26 and at the bight of the rolls subjecting the overlapping marginal portions progressively to pressure across their entire width while the full vertex portion of the binding strip is simultaneously given the circular conformation shown in this figure.

When the binding is to be attached by flat stitching and turning as shown in FIG. 4 the binding strip is folded unevenly as shown'in FIG. 9. For example, the upper marginal portion of the binding is substantially narrow than the lower portion thereof. When this binding 15 is applied it is first attached to the part 10 of the upper by the stitch line 16 formed while the binding lies flat. The binding is then turned and folded over its attached margin and over the edge of the part 10 and finally secured by the second stitch line 1. The treatment above described imparts to the binding strip a cross sectional curvature as indicated in FIGS. 2 and 3, although the character and consistency of the binding has been improved much more than would be indicated by the slight change that has occured in its appearance. The treated binding is now found to run freely with slight and uniform drag in the guide 26 and to act in respect to handling as high grade binding usually costing the supplier substantially twice as much.

The binding strip may sometimes take the form of a thin leather facing reinforced by a fabric tape. It has been found that such composite binding may also be substantially improved in its characteristics by being sub- It has been noted that the binding comes to the customer in strip form, It is converted to this form by the supplier who selects the skins, strips them up and joins the strips together. He then levels or skives the composite strip to an even weight and sends it to the customer in various forms, as on spools or in coils, depending upon its ultimate use. In addition to the binding of shoe uppers the preformed binding strip may be used to advantage for binding garments, gun cases, gloves, golf bags and a host of other articles. For these purposes the binding may be made up in widths from one-eighth of an inch to three inches, and from .010 to .110 inch in thickness from kid leather all the way up to calf, side leather, etc.

Certain difficulties encountered in the use of unpreformed binding have been noted but in addition it frequently happens that the drag of such binding in the guide of the sewing machine tends to narrow the width of the binding as it is applied and also to tear the joints or laps in the strip. There is also a tendency of puckering both the article being bound and the binding itself, especially when stiff places are encountered in the untreated material. These difiiculties vanish when the binding has been preformed in accordance with the process of my invention.

It will be further understood that in the preforming operation the folding of the strip may be unsymmetrical as indicated in FIG. 9 or in any varying ratio of the overlapping marginal portions, In preforming binding for stitching and turning as in FIG. 4 the binding is given a two step treatment, that is to say, it is first run through rolls that fold it close to one edge, adapting it to take the first fold, and then run through rolls that fold it a little offset from the middle, adapting it to take the second fold as it wraps itself over the edge of the shoe upper.

In general the relation of the preforming dimension varies directly with the thickness of the binding and the thickness of the article to be bound andthis, of course, requires rolls of various dimensions and patterns.

The rolls and the break they produce in the stock must be made to fit the job. For example, in dealing with a one inch binding for a one-eighth inch shoe upper a set of rolls is required that will preform the binding to awidth of one-eighth inch.

Having thus disclosed my invention and described in detail certain illustrative embodiments and examples 4 thereof, I claim as new and desire to secure by Letters Patent:

1. The process of preforming and improving leather binding strip, comprising the steps of folding the strip to present overlapping marginal portions, and subjecting the overlapped portions to progressive rolling pressure While confining the fold vertex of the strip within a passage of greater dimensions than the combined thickness of said overlapped portions.

2. The process of preforming leather binding strip, comprising progressively folding the strip to present overlapping marginal portions and progressively advancing the folded strip between pressure rolls that press the overlapping marginal portions of the strip and at the same time impart a bead formation of circular cross section to the fold vertex of the strip.

3. The process of preforming leather binding strip as defined in claim 2, further characterized in that the binding strip is folded to present overlapping marginal portions of unequal width,

4. The process of preforming a composite binding strip having a facing of leather reinforced by an adhesively attached tape of fabric, comprising the step of progressively forming a longitudinal fold vertex in the strip by overlapping its marginal portions, and then subjecting the strip to rolling pressure throughout its entire width and at the same time imparting a circular bead formation to its fold vertex portion.

5. The process of preforming leather binding strip comprising progressively folding the strip to present overlapping marginal portions of unequal width, progressively advancing the folded strip between pressure rolls of a contour conforming the fold vertex of the strip into a rounded head, then folding the strip to present overlapping margins of substantially equal widths and again subjecting said overlapping marginal portions to rolling pressure.

References Cited in the file of this patent UNITED STATES PATENTS 116,123 Webber June 20, 1871 251,293 Rogers Dec. 20, 1881 342,946 Ames June 1, 1886 544,399 Arnold Aug. 13, 1895 

